Zehetmayer M, Rainer G, Turnheim K, Skorpik C, Menapace R
Department of Ophthalmology and Pharmacology, University of Vienna, Austria.
J Cataract Refract Surg. 1997 Nov;23(9):1390-3. doi: 10.1016/s0886-3350(97)80120-4.
To evaluate and compare the efficacy of a sodium-bicarbonate-adjusted preparation of lidocaine 4% (pH = 7.2) and standard lidocaine (pH = 5.2) for topical anesthesia in clear corneal cataract surgery.
Department of Ophthalmology, University of Vienna, Austria.
In a prospective, randomized, double-blind clinical trial, clear corneal cataract surgery was performed under topical anesthesia in 44 eyes of 34 patients. In 22 eyes, pH-adjusted lidocaine 4% was administered; in the other 22, standard lidocaine 4%. Aqueous and serum concentrations of lidocaine were measured by high-performance liquid chromatography and ultraviolet detection. Subjective pain was assessed using a visual analog scale of no pain (0%) to worst imaginable pain (100%). On the first postoperative day, visual acuity, intraocular pressure, and corneal staining with fluorescein were examined.
In the pH-adjusted lidocaine group, significantly higher lidocaine concentrations were found in the aqueous humor (15.06 microg/mL +/- 8.2 [SD] versus 4.75 +/- 3.5 microg/mL; P < .0001). In all samples (n = 8), serum lidocaine concentrations were below a minimum detectable level of 0.02 microg/mL. Subjective pain ratings were similar in the pH-adjusted and standard lidocaine groups (mean 9.73 +/- 10.4% and 10.0 +/- 15.4%, respectively). There was no significant between-group difference in intraoperative and postoperative outcomes.
In this study, pH-adjusted lidocaine 4% was a safe, effective topical anesthetic for clear corneal surgery and had minimal local and systemic toxicity. Administration of pH-adjusted lidocaine 4% resulted in significantly higher aqueous humor lidocaine concentrations than administration of standard lidocaine 4%.
评估并比较4%碳酸氢钠调节的利多卡因制剂（pH = 7.2）与标准利多卡因（pH = 5.2）在透明角膜白内障手术中局部麻醉的效果。
奥地利维也纳大学眼科。
在一项前瞻性、随机、双盲临床试验中，对34例患者的44只眼进行透明角膜白内障手术并实施局部麻醉。22只眼给予pH调节的4%利多卡因；另外22只眼给予标准4%利多卡因。采用高效液相色谱法和紫外线检测法测量利多卡因的房水和血清浓度。使用视觉模拟评分法评估主观疼痛，范围从无疼痛（0%）到难以想象的最严重疼痛（100%）。术后第一天检查视力、眼压和荧光素角膜染色情况。
在pH调节的利多卡因组中，房水中利多卡因浓度显著更高（15.06微克/毫升±8.2[标准差]，而4.75±3.5微克/毫升；P < 0.0001）。在所有样本（n = 8）中，血清利多卡因浓度低于最低可检测水平0.02微克/毫升。pH调节的利多卡因组和标准利多卡因组的主观疼痛评分相似（分别为平均9.73±10.4%和10.0±15.4%）。术中及术后结果在两组之间无显著差异。
在本研究中，4%pH调节的利多卡因是透明角膜手术安全、有效的局部麻醉剂，局部和全身毒性极小。给予4%pH调节的利多卡因导致房水中利多卡因浓度显著高于给予标准4%利多卡因。
